What Factors Affect a Sufficient Tobramycin Dose?

The main factors affecting the sufficient tobramycin dose are the clinical condition, or disease it is being used to treat; the pharmaceutical form in which it is given, i.e. injectable, inhaled via nebulization or topical, such as eye drops or ear drops; response to the drug, and tolerance. The correct tobramycin dose will be determined by the treating doctor. Tobramycin is an antibiotic used to treat certain bacterial infections and in most countries it is available by prescription only and may be known by different trade names, according to manufacturer.

Tobramycin belongs to the class of antibiotic drugs called aminoglycosides, which work by inhibiting bacterial protein synthesis which, in essence, kills the bacteria. It is used to treat serious infections caused by some Gram-negative bacilli, including Pseudomonas and some mycobacterial infections.

When taken orally, tobramycin is not absorbed in the gut, so it is only given as an injection, either IV or intramuscularly, if used systemically. Often the treating doctor will do a culture on the patient's blood, urine or sputum to establish whether the bacteria is sensitive to the drug. The tobramycin dose will be determined by the severity of the infection and the size of the patient and is continued usually for seven to 10 days. The tobramycin dose may be adjusted in patients with kidney dysfunction.

The inhaled preparation of tobramycin is used mainly in patients with cystic fibrosis, to treat infections of the lung. The tobramycin is given via nebulisation, which instills tiny droplets of the drug directly into the lungs. The usual tobramycin dose for inhalation is 300 mg twice daily for 28 days, followed by a 28-day drug-free period. This schedule continues as long as benefit is derived from the treatment, as determined by the treating doctor.

Tobramycin may also be used topically, that is either as an eye drop or ointment or an ear drop. It is important that this is done under supervision of a doctor to ensure the treatment is correct. The dose given is usually one to two drops given two to five times a day, depending on the severity of the infection. In the case of severe infections, it may be given even more frequently. The prescribed dosage and frequency of use should never be exceeded.

As with any medication, tobramycin may interact with other medications or be contraindicated in people with some underlying conditions and these should be discussed with the prescribing doctor. Adverse effects, such as kidney toxicity and hearing loss, may occur and will be monitored for by the treating doctor. If any untoward effect should occur, medical attention should be sought immediately.